Mechanical properties of titanium-reinforced and zirconia-reinforced Mg-based bulk metallic glass

• Main Author: Oon, Justin Junjie.
• Other Authors: Tan Ming Jen
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Materials::Mechanical strength of materials
• Online Access: http://hdl.handle.net/10356/54027
• Institution: Nanyang Technological University

Since the first discovery of the amorphous metal or also known as the metallic glass in 1960s, this class of material has attracted material researchers all around the world due to its excellent properties it possess. For this project, the focus is on Mg-based bulk metallic glasses (BMG). This particular BMG have possibilities as many applications such as bio-degradable implants, due to their exceptional strength and biocompatibility. However, these BMG has also its disadvantage such as low ductility when subjected to loading at ambient temperature. These mechanical properties could however, be altered through means of composite. In this project, Titanium-reinforced and Zirconia-reinforced are fabricated, characterized and subjected to mechanical testing to determine the mechanical properties of the composite material. Different composition of the two composite were fabricated through means of an injection casting machine. The samples were then characterized using X-ray Diffraction (XRD), Differential Scanning Calorimeter (DSC) and Scanning Electron Microscopy (SEM). Mechanical test such as compression test and Vicker’s hardness test were conducted to evaluate the mechanical properties of the composites Experiments showed that the Zirconia-BMG composite displayed improvements in both its compressive strength and hardness. Improvement in strength is probably due to good adhesion and thus effective load transfer between the matrix and reinforcement material and coupled with the transformation toughening mechanism of YSZ. The ability of YSZ to impede the movement of atoms is far greater than that of the BMG matrix, therefore with effective load transfer, the overall hardness of the reinforced sample has been improved. Titanium-BMG composite on the other hand showed no signs of improvements to the mechanical properties. This result showed possibility that the adhesion between Titanium reinforcement and the matrix is relatively poor and therefore resulting in ineffective load transfer from the matrix to the reinforcement.